Sports Medicine: Injuries, Technique and Conditioning

By Scott Riewald, Ph.D.

IntroductionInjuries are a fact of life in almost every physical activity, and tennis is no exception. With the amount of tennis that today’s high performance players play it is very unlikely that anyone will make it through their career without sustaining an injury of some sort. With that said, it is important to realize that not all injuries are created equal. Some injuries, like a sprained ankle, are accidents and “just seem to happen;” there is not much a player can do to “better prepare” for that type of scenario. However, there are other injuries that are directly related to preparation and technique. These are injuries that likely can be avoided if a player takes the time to learn, and use, proper technique while also conditioning the body to handle the demands of tennis.

Importance of Technique in Injury PreventionTechnique should be one of the cornerstones of effective, injury-free tennis. The body is an amazing structure and it is incredible what players can make it do on the tennis court. However, there are also limits to how the body can perform. When the muscles, tendons and bones are pushed past their limits, injuries can occur. Probably the type of injury most coaches and players are familiar with is tendonitis – especially in the shoulder, elbow or knee. Most types of tendonitis occur as the result of overusing or placing excessive stress on a muscle or tendon. In many instances the added stresses the body experiences are due to improper technique. When practicing the serve, for example, fatigue in the shoulder and scapular muscles and can lead to a breakdown in technique, which in turn places undue stress on the muscles and tendons of the rotator cuff. While it is not likely that the amount of damage done during one “poor serve” alone cause shoulder pain, every time technique is compromised, a little more damage is done. Over time these repetitive “micro-traumas” add up to produce an injury--in this case tendonitis in the shoulder.

Historically, the lower back has been another place where injuries occur with regularity. Doug Spreen, one of the Sports Medicine Trainers on the ATP Tour has noted an increased number of low back injuries, and an increased number of tournament withdrawals, over the past two years. While these injuries may be fairly common, most players recover from these injuries relatively rapidly and the number of players who are knocked out for the season is small.

Technique can have an impact on more than just repetitive use types of injuries. Dr. David Altchek, medical director for the ATP Tour, commented that, “There have always been, what we’ll call minor injuries – like injuries to the foot, elbow, or lower back - that may impair performance or result in a small amount of lost playing time. But over the past four years we have really seen an increase in hip injuries and shoulder injuries that require surgery. These are major injuries that cause players to lose a great deal of playing time.”

The increased incidence of hip and severe shoulder injuries likely has a lot to do with technique and how play has changed over the years. “Pace plays a greater role in today’s style of play,” says Dr. Altchek. “Players have always served hard. However, it used to be that a player would have a powerful serve and then play the point looking for an opening and an opportunity to score. Now, with the improved racquet technology, it is possible to win points from everywhere. Players are hitting more powerful shots that they were five years ago. This places the body, particularly the hip and shoulder, under much greater stress.” Additionally, more players are hitting with an open-stance forehand. This is another factor that can contribute to injury since this style of tennis subjects the rear hip to much larger forces as the player generates the force and power to swing the racquet.

Another area where we are seeing a greater number of injuries is the wrist. Kathleen Stroia, Associate Vice President of Sport Science and Medicine for the WTA comments that, “With the increased wrist action used by many players today, we are seeing a greater number of wrist injuries.” As the wrist is engaged during a shot the structures of the wrist are subjected to larger forces. As with tendonitis, each stroke likely does not produce an injury, but over time these large stresses can lead to and overuse type of injury.

The techniques used in tennis are always evolving. The power of today’s game has “forced” players to adopt a style that differs greatly from what was seen 10 years ago. Because of the changing nature of tennis and how it is played, it is important to realize that a player cannot just change technique without preparing the body to handle the added stresses and force it will experience. This brings us to the importance of engaging in a proper strength and conditioning program.

Importance of Conditioning in Injury PreventionAs the physical demands of tennis change, proper conditioning plays an increasingly greater role in injury prevention. The body needs to be better conditioned to perform at these fast paces and generate the power that is behind many of today’s tennis shots. Spreen states, “There has definitely been an increase in the number of injuries over the past 10 years. I believe much of that can be attributed to the fact that guys are hitting the ball much harder that they were 10 years ago. The players must also move more quickly and explosively to go get balls. If guys are going to play with more power, the body has to be trained to be able to generate more power.”

That is the key. The body must be prepared to withstand the repeated powerful shots today’s player is expected to generate. However, in many instances, the body is not prepared to handle these demands. Often times players exhibit significant strength imbalances throughout the body, have poor posture, have limited strength in the body’s powerhouse--the core, or exhibit limited range of motion about certain joints.

When a player has a strength imbalance, it means that one group of muscles acting at a joint is appreciably stronger (or weaker) than the other muscle groups that work at that joint. For example, the muscles that internally rotate the shoulder are usually extremely strong in tennis players, but the external rotators are “weak” in comparison. These strength imbalances can cause the shoulder joint to move abnormally, which can lead to injury. To reduce the risk of injuries due to strength imbalances it is important to train all muscle groups around a joint and not just the ones that “make sense” for playing tennis. This approach to strength training will promote proper joint function.

Another place where many tennis players could improve is in the area of core body strength. Kathleen Stroia says, “When I first started with the WTA tour 10 years ago, most of the injuries we saw were tendonitis, now we see this type of pain as more of a symptom of a larger problem – namely muscular instability in the shoulder and/or weakness in the core of the body.” The core of the body, which includes the abdominal and lower back muscles, provides power and balance to a tennis player. Watch Andre Agassi hit a baseline forehand and you will see that he is not just using his arms to generate the power in their swings, he is using his entire body.

The body is made up of a series of segments, a kinetic chain (which is discussed in greater detail below). This chain allows power to be transferred through the body and to the racquet. The core of the body is one link in this chain. If that link breaks, or becomes weaker over the course of a practice or a match, undue stresses are placed on other parts of the body. To be effective, tennis players must consistently train the core of the body to be able to generate the power and balance that is needed by today’s tennis player.

The third area that players typically need to develop if flexibility. One of the areas Dr. Altchek identified as a weakness in today’s players is inflexibility, “particularly in the shoulders, hips and lower back. Inflexibility causes forces to concentrate at certain points since joints cannot move through a complete range of motion. This places added stress on the other structure around the joint, possibly leading to injury.” A proper part of any strength and conditioning program should be flexibility training. Long past are the days where stretching meant only performing static (non-moving and not very exciting) stretches. Today’s flexibility programs involve performing dynamic movements in which players stretch while moving in ways they might on the court. Also called a dynamic warm-up, dynamic stretching warms up the player while also improving flexibility. Some sort of flexibility program should be included in every athlete’s training plan.

Kinetic ChainTechnique and conditioning both come together when we talk about the kinetic chain. “Kinetic chain” is a term used to describe the linkage between body segments that allows power from one body part to another, and eventually to the racquet.

In tennis, the player is able to generate a great deal of force and power with the legs as they interact with the ground – this is the first and one of the most powerful links in the chain. The power developed by the legs can then be transferred to the trunk of the body where the core muscles of the abdomen and lower back can add to the power that is generated. This process continues and power is transferred to the upper body, the shoulder, elbow and wrist until it finally reaches the tennis racquet. In a player with good technique, power “flows” from the ground to the racquet.

The keys to this flow are proper timing of the tennis stroke and coordinated muscle action. The different links of the body are in essence “connected” by muscles. Strong muscles can provide a rigid link between segments. At the same time, weak or fatigued muscles can be seen as a broken link. When a link breaks, it generally is due to a lack of strength, fatigue, or a strength imbalance at a certain joint.

If any link in the chain is weak, the tennis player will be forced to adapt and “over-stress” another part of the body. Also, when a link is weak or breaks, another part of the body must pick up the slack and compensate for the power that was lost through the broken link. It is easy to imagine a player’s core muscles fatiguing over the course of a three-set match. As the abdominal and lower back muscles fatigue they are unable to generate the force they could at the start of the match. At some point the muscles will weaken to the point that the “link” between the lower body and the torso is broken. When this happens, much of the power generated by the legs never makes it to the racquet during the serve or a forehand. If the player still wants to impart the same velocity the ball, they will have to use the links closer to the end of the chain (shoulder, elbow, wrist) to make up for the lost power. This sets the athlete up for injury.

ConclusionInjuries can be very damaging to a player’s season. An injury occurring at the wrong time can result in a loss of practice time and possible a drop in the rankings. As a result, every coach and player should want to do everything possible to minimize the risk of injury. This article has outlined two of the factors that can contribute to an injury in tennis players: poor technique and poor conditioning. Not all injuries can be eliminated, but by following a couple of basic points, their incidence can be reduced.

Learning and using proper technique.

Strengthening the core of the body.

Strengthening all muscles of the body and not just those that make sense for tennis.

Maintaining “normal” ranges of motion about joints by engaging in a flexibility program.

By following these steps your players will be on the way to reducing the risk of injury and better tennis.